Abstract: A method of performing fault detection during computations relating to a neural network comprising a first neural network layer and a second neural network layer in a data processing system, the method comprising: scheduling computations onto data processing resources for the execution of the first neural network layer and the second neural network layer, wherein the scheduling includes: for a given one of the first neural network layer and the second neural network layer, scheduling a respective given one of a first computation and a second computation as a non-duplicated computation, in which the given computation is at least initially scheduled to be performed only once during the execution of the given neural network layer; and for the other of the first and second neural network layers, scheduling the respective other of the first and second computations as a duplicated computation.

Abstract: A communication device configured to communicate according to a data protocol in which data is carried in packets over a serial data link and the communication device is arranged: to form packets for transmission over the link in such a way that every packet commences with a first bit value; and between transmitting successive packets to continuously transmit a second bit value opposite to the first bit value over the link.

Abstract: A method of reconfiguring a current debug configuration of a debug unit connected to a peripheral circuit on an integrated circuit chip. The method comprises the debug unit collecting debug data of the peripheral circuit and outputting the debug data in a message stream. The debug unit receives a debug reconfiguration command. The debug unit transmits an indication of the current debug configuration, then reconfigures the current debug configuration to a new debug configuration in accordance with the debug reconfiguration command, then transmits an indication of the new debug configuration. The indication of the current debug configuration and the indication of the new debug configuration are transmitted adjacent to the debug data in the message stream.

Abstract: An interconnect, and method of handling supplementary data in an interconnect, are provided. The interconnect has routing circuitry providing a plurality of paths, and routing control circuitry to use the plurality of paths to establish routes through the interconnect between source devices and destination devices coupled to the interconnect, to enable system data to be routed through the interconnect between the source devices and the destination devices. The system data relates to functional operation of a system comprising the interconnect, the source devices and the destination devices. At least a subset of the paths are redundant paths whose use by the routing control circuitry provides the system data with resilience to faults when routing the system data through the interconnect.

Abstract: A method of reconfiguring a current debug configuration of a debug unit connected to a peripheral circuit on an integrated circuit chip. The method comprises the debug unit collecting debug data of the peripheral circuit and outputting the debug data in a message stream. The debug unit receives a debug reconfiguration command. The debug unit transmits an indication of the current debug configuration, then reconfigures the current debug configuration to a new debug configuration in accordance with the debug reconfiguration command, then transmits an indication of the new debug configuration. The indication of the current debug configuration and the indication of the new debug configuration are transmitted adjacent to the debug data in the message stream.

Abstract: A method of reconfiguring a current debug configuration of a debug unit connected to a peripheral circuit on an integrated circuit chip. The method comprises the debug unit collecting debug data of the peripheral circuit and outputting the debug data in a message stream. The debug unit receives a debug reconfiguration command. The debug unit transmits an indication of the current debug configuration, then reconfigures the current debug configuration to a new debug configuration in accordance with the debug reconfiguration command, then transmits an indication of the new debug configuration. The indication of the current debug configuration and the indication of the new debug configuration are transmitted adjacent to the debug data in the message stream.

Abstract: A method of tracing transactions on an integrated circuit chip. The method comprises, for each transaction: extracting the transaction from interconnect circuitry of the integrated circuit chip, the transaction comprising an address signal and a data signal; applying a filtering condition to the address signal; only if the address signal does not fail the filtering condition, storing the address signal in an address trace buffer; storing the data signal in a data trace buffer; applying a triggering condition to the stored transaction; and outputting the stored transaction if the stored transaction matches the triggering condition.

Abstract: A communication device configured to communicate according to a data protocol in which data is carried in packets over a serial data link and the communication device is arranged: to form packets for transmission over the link in such a way that every packet commences with a first bit value; and between transmitting successive packets to continuously transmit a second bit value opposite to the first bit value over the link.

Abstract: An interconnect, and method of handling supplementary data in an interconnect, are provided. The interconnect has routing circuitry providing a plurality of paths, and routing control circuitry to use the plurality of paths to establish routes through the interconnect between source devices and destination devices coupled to the interconnect, to enable system data to be routed through the interconnect between the source devices and the destination devices. The system data relates to functional operation of a system comprising the interconnect, the source devices and the destination devices. At least a subset of the paths are redundant paths whose use by the routing control circuitry provides the system data with resilience to faults when routing the system data through the interconnect.

Abstract: A communication device configured to communicate according to a data protocol in which data is carried in packets over a serial data link and the communication device is arranged: to form packets for transmission over the link in such a way that every packet commences with a first bit value; and between transmitting successive packets to continuously transmit a second bit value opposite to the first bit value over the link.

Abstract: A method of profiling transactions on an integrated circuit chip. The method comprises, for each transaction: extracting the transaction from interconnect circuitry of the integrated circuit chip; and filtering the transaction at a filtering circuit to determine which passband a parameter of the transaction lies within; sending an increment signal to a counter of a bank of counters, the counter having a counter value indicative of a number of transactions having the parameter lying within the passband; and outputting the counter values of the bank of counters.

Abstract: Roughly described, a method of powering down a portion of an integrated circuit chip, the portion of the integrated circuit chip comprising a plurality of peripheral circuits, each peripheral circuit being connected to a respective debug unit, the method comprising: prior to power down, extracting from each debug unit configuration information of that debug unit; storing the configuration information of the debug units in a memory on the integrated circuit chip during power down of the portion of the integrated circuit chip; and on power up, restoring the configuration information of each debug unit to that debug unit prior resuming operation of that debug unit and the peripheral circuit connected to that debug unit.

Abstract: An integrated circuit chip comprising system circuitry and debugging circuitry. The system circuitry comprises a peripheral circuit. The debugging circuitry comprises a debug unit and a debug adapter. The debug unit is connected to the peripheral circuit. The debug adapter interfaces between the debug unit and a debug controller. The debug adapter is configured to receive a sequence of debug commands from the debug controller, each debug command instructing the debug unit to perform an action other than responding to a poll. In respect of each debug command, the debug adapter sends the debug command to the debug unit, and polls the debug unit to query whether the debug unit has performed the action instructed in that debug command.

Abstract: A method of reconfiguring a current debug configuration of a debug unit connected to a peripheral circuit on an integrated circuit chip. The method comprises the debug unit collecting debug data of the peripheral circuit and outputting the debug data in a message stream. The debug unit receives a debug reconfiguration command. The debug unit transmits an indication of the current debug configuration, then reconfigures the current debug configuration to a new debug configuration in accordance with the debug reconfiguration command, then transmits an indication of the new debug configuration. The indication of the current debug configuration and the indication of the new debug configuration are transmitted adjacent to the debug data in the message stream.

Abstract: A method of reconfiguring a current debug configuration of a debug unit connected to a peripheral circuit on an integrated circuit chip. The method comprises the debug unit collecting debug data of the peripheral circuit and outputting the debug data in a message stream. The debug unit receives a debug reconfiguration command. The debug unit transmits an indication of the current debug configuration, then reconfigures the current debug configuration to a new debug configuration in accordance with the debug reconfiguration command, then transmits an indication of the new debug configuration. The indication of the current debug configuration and the indication of the new debug configuration are transmitted adjacent to the debug data in the message stream.

Abstract: Roughly described, a method of restricting access of a debug controller to debug architecture on an integrated circuit chip, the debug architecture comprising an access controller, a plurality of peripheral circuits, and a shared hub, the shared hub being accessible by the access controller and the plurality of peripheral circuits, the method comprising: at the access controller, authenticating the debug controller; at the access controller, following authentication, assigning to the debug controller a set of access rights, the set of access rights granting the debug controller partial access to the debug architecture; and after assigning the set of access rights, allowing the debug controller access to the debug architecture as allowed by the set of access rights.

Abstract: Roughly described, a method of restricting access of a debug controller to debug architecture on an integrated circuit chip, the debug architecture comprising an access controller, a plurality of peripheral circuits, and a shared hub, the shared hub being accessible by the access controller and the plurality of peripheral circuits, the method comprising: at the access controller, authenticating the debug controller; at the access controller, following authentication, assigning to the debug controller a set of access rights, the set of access rights granting the debug controller partial access to the debug architecture; and after assigning the set of access rights, allowing the debug controller access to the debug architecture as allowed by the set of access rights.

Abstract: Roughly described, a method of restricting access of a debug controller to debug architecture on an integrated circuit chip, the debug architecture comprising an access controller, a plurality of peripheral circuits, and a shared hub, the shared hub being accessible by the access controller and the plurality of peripheral circuits, the method comprising: at the access controller, authenticating the debug controller; at the access controller, following authentication, assigning to the debug controller a set of access rights, the set of access rights granting the debug controller partial access to the debug architecture; and after assigning the set of access rights, allowing the debug controller access to the debug architecture as allowed by the set of access rights.

Abstract: Roughly described, a method of restricting access of a debug controller to debug architecture on an integrated circuit chip, the debug architecture comprising an access controller, a plurality of peripheral circuits, and a shared hub, the shared hub being accessible by the access controller and the plurality of peripheral circuits, the method comprising: at the access controller, authenticating the debug controller; at the access controller, following authentication, assigning to the debug controller a set of access rights, the set of access rights granting the debug controller partial access to the debug architecture; and after assigning the set of access rights, allowing the debug controller access to the debug architecture as allowed by the set of access rights.

Abstract: A method of functionality testing system circuitry on an integrated circuit chip, the system circuitry comprising a plurality of sub-circuits and the integrated circuit chip further comprising debugging circuitry, the debugging circuitry comprising variability circuitry. The method comprises: at the system circuitry, performing a function by the sub-circuits performing concurrent actions; at the variability circuitry, altering relative timing of the concurrent actions so as to increase the likelihood of one or more errors in the system circuitry's performance of the function; and at the debugging circuitry, recording one or more errors in the system circuitry's performance of the function.